where γαβ is the interfacial energy

where γαβ is the interfacial energy between crystal phases and ΔS the entropy of fusion [7]. The undercooling values with respect to the eutectic temperature are plotted in Fig. 2b. They are limited to a few degrees whereas they are in between 40 K and 45 K with respect to the liquidus.The undercooling is highest in the portion of the samples which solidifies at first in contact with the quenching medium, then remains almost steady. At each temperature, the eutectic growth rate, V, is then determined [6] using λ2V ¼ 8DLð Þ TI 2 γαβΔS m ΔC ð2Þ where DL(TI) is the interdiffusion coefficient at the interface temperature, TI, m is the average liquidus slope, and ΔC the difference in composition between crystal phases